1. Field of the Invention
The present invention relates to nanoscience, nanoparticles and, more specifically, to a highly uniform, table, and tailorable core-void-shell morphology.
2. Description of the Related Art
Stainless metal interfaces resist bulk oxidation and consist of FeCr alloys. This stainless characteristic is the result of an oxidation process in which a passivating layer of Cr2O3 forms which limits further molecular oxygen transport. Like bulk materials, the oxidation of nanomaterials is a critically important phenomenon the extent of which determines the materials function. This is especially true for first row transition metals. While the synthesis of oxide nanomaterials is well established, approaches to resist oxidation are varied, and recent studies have in turn welcomed oxidation as a synthetic tool to manipulate nanoparticle morphology and microstructure.
Oxidation in iron based nanostructures lead to Kirkendall diffusion, which can form an assortment of hollow nanostructures, ranging from nanowires on a solid support, to nanocubes, and nanospheres. The experimental implementation of Kirkendall diffusion using Co nanoparticles (NPs), upon sulfidation of solid Co NPs, showed well defined hollow morphologies that resulted in an assortment of CoxSy phases. It was further shown that the sulfidation of Pt/Co core/shell NPs resulted in novel core-void-shell morphologies, due in large part to the resistance of the Pt core to oxidation.
These examples of ‘vacancy coalescence’ have since prepared a number of hollow nanostructures, like Fe, Fe3O4, Co, Ni and Cd NPs. Vacancy coalescence can be considered an extension of the Kirkendall effect, when diffusion is confined to a three dimensional nanomaterial, and is the result of the nonreciprocal diffusion of materials within the NP, electrical contact between the core and shell, as well as defect concentration. Parameters that can tune this phenomena include the diffusivity of the atoms involved, the oxidation products, NP morphology, and the size of the starting material. To date little work has been described that uses alloy interfaces, or stainless materials, to control Kirkendall kinetics and void formation.